qca2 - Qt Cryptographic Architecture

Taking a hint from the similarly-named Java Cryptography Architecture,
QCA aims to provide a straightforward and cross-platform crypto API,
using Qt datatypes and conventions. QCA separates the API from the
implementation, using plugins known as Providers. The advantage of this
model is to allow applications to avoid linking to or explicitly depending
on any particular cryptographic library. This allows one to easily change
or upgrade crypto implementations without even needing to recompile the
application!